January 28, 2019 11:15 a.m.
London researchers have linked a specific injectable opioid to an increase in a potentially fatal heart infection in Ontario.
The study by the Lawson Health Research Institute, the Institute of Clinical Trials Sciences (ICES) and the Western University found an increase in infective endocarditis, a serious bacterial heart infection among those using injecting drugs coincided with an increase in the number of prescriptions of emitted hydromorphone.
Researchers examined 60,529 hospital admissions related to injecting drug use throughout the province between 2006-2015 and identified 733 patients who had infective endocarditis. The risk of life-threatening infection jumped from 13.4 admissions to 35.1 admissions every three months during the study period.
At the same time, the number of prescriptions for hydromorphone increased from 16% of all opioid prescriptions in 2006 to 53% by 2015.
"The opiate crisis is one of the most pressing health problems of our time. Our findings not only confirm an increasing risk of infective endocarditis in people who inject drugs but also provide the first evidence as to why this may be happening, "said Dr. Matthew Weir, an associate scientist at ICES and associate scientist at Lawson.
Controlled release hydromorphone, the most common form of the drug, can be difficult to dissolve, leaving waste in injection equipment that tends to be reused or shared by injecting drug users. This allows for multiple opportunities for bacterial contamination, increasing the chances that bacteria will be injected when the equipment is used next.
Infective endocarditis occurs when the lining of the heart becomes infected.
The researchers predicted that the rise of the disease at risk of death would coincide with the elimination of the easy-to-dissolve controlled release oxycodone market in 2011. But in a surprising finding, the researchers determined that increased infective endocarditis began in 2010 .
"While time was not what we expected, we found a correlation between increased prescriptions for infective endocarditis and hydromorphone," said Sharon Koivu, a scientist Lawson and associate professor at Western's Schulich School of Medicine & Dentistry. "Our research is now focused on a better understanding of the potential relationship between hydromorphone injection and the risk of infective endocarditis."
Studies in progress by the team of researchers are examining whether bacteria causing infective endocarditis are more likely to survive on equipment used to prepare hydromorphone compared to other drugs.
The study was published Monday in the Canadian Medical Association Journal.